Feb., 1913
T H E JOLTRA\.\-.4L OF I-VDUSTRIAL A N D ENGINEERING CHE.WISTRk t
Utes and finally quickly weighed. Weight of water, after deducting blank, multiplied b y 0.8888 divided b y 2 5 equals oxygen. A blank should be run frequently, adhering t o all details as t o time of heating furnaces, desiccating U tube, etc. Usually the blank found varies between 0.0015a n d 0 . 0 0 2 5 gram. For samples of tungsten powder the same procedure is carried out except that a smaller sample is taken varying from one t o ten grams according t o the amount of oxygen present. The following table gives results on several samples in duplicate by the above described procedure : Oxygen C
NO.
Mn
S
P
. . . . . . 1.15 0.31
Si-
0.018 0.011 0.015 0.010 3 Crucible steel.. 1.14 0.33 0.016 0.009 41 Basic open hearth steel.. 0.07 0.06 0.019 0.008 5 Basic open hearth steel., . 0 .OS 0.22 0.016 0.008 6 Swedish wrought iron. , . . 0 . 0 6 0.17 0.019 0.012 7 Domestic wrought iron.. . 0.69 trace 0,009 0,007 8 Domestic wrought iron... 0.73 . . 0.009 0.007 9 Acid open hearth steel.. .. 0.36 0 . 6 9 0.040 0,046 10 Bessemer steel.. 0 . 4 6 0.72 0.041 0.095
......
..........
1 . 1 7 0.31
.
......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
0.22 0.039 0.037 0.22 0.035 0.035 0.21 0.044 0.045 0 .OS 0.113 0.115 0.01 0.079 0.072 0.02 0.345 0.353 0.06 0.069 0.076 0.06 0.090 0.089 0.03 0.043 0.042 0.09 0.058 0.060 . . . 2.57 2.57 . . . 1.37 1.34 . . . 0.55 0.56 . . . 1.02 1.05
This sample fractured badly in rolling.
Numbers I, 2 and 3 were three ingots made under as nearly the same conditions as possible. It is not intended t h a t the above table should be typical as to the oxygen content t h a t exists in the different classes of steel. I n many samples of crucible steel it is much lower than those cited. CRESCENTLABORATORY CRUCIBLESTEELCo. OF AMERICA ASPINWALL,PA.
THE VOLUMETRIC DETERMINATION OF MANGANESE IN ROCK, SLAGS, ORES AND SPIEGELS . B y F. J. METZGERAND L. E. MARRS Received November 1, 1912
A new and accurate method for the determination of manganese and its application t o the analysis of iron and steel has been published by us in THISJ O U R N A L (3, 333). The method has since been applied to rock, slags, ores, and spiegels and it is the purpose of this paper to report on these. Analyzed samples of rocks and of a manganese ore were furnished by W. F. Hillebrand, of the Bureau of Standards. We desire to express our gratitude t o Dr. Hillebrand for this material assistance and for the kindly interest he has shown during the progress of our work. Rock.-Here the manganese content is a p t to be very low and for accurate work a portion of from two to five grams should be taken for analysis. Place the weighed portion in a platinum dish; add 5-15 cc. dilute sulfuric acid (I : 2) and boil; add 5-15 cc. hydrofluoric acid and boil until the rock is completely decomposed. Add 5-10 cc. dilute nitric acid ( I : I) and 2 or 3 cc. of concentrated sulfuric acid; remove from the flame and add about one gram ammonium persulfate in small portions: when evolution of gas has ceased, evaporate t o fumes of sulfur trioxide,
125
cool, add 5 0 cc. water, boil and cool. Transfer t o a wax beaker, add 5 grams ammonium fluoride and 2 5 cc. hydrofluoric acid (making a total volume of about I O O cc.) and titrate t o a permanent pink color with potassium permanganate solution (approximately
N/30). The value of the permanganate in terms of iron multiplied b y 0 . 7 8 6 8 2 gives the value in terms of manganese, or by 1.01601in terms of MnO. Slag.-Weigh out 0.2-1.0 gram and treat as in rock unless the manganese content is high. If more than about 20-30 mg. of manganese is present in the solution titrated, a brown color will appear toward the end of the titration, but, with a very little experience, as much as 60 mgs. may be titrated with accuracy using a N/IO(approx.) permanganate solution. With high percentages of manganese, the titration of a n aliquot part of the solution is much more accurate than weighing out exceedingly small amounts. I t has been found best to titrate with a volume of about 150 cc. containing about 60 mgs. of manganese when more than 40 per cent. of manganese is t o be determined. If much manganese is present in the solution. oxidized manganese compounds may appear after the addition of the nitric acid t o the mixture; the authors have found, on several . occasions, a strong permanganate color on taking the mixture to fumes of sulfur trioxide. When this occurs, cool; add 50 cc. water; cool again; add hydrogen peroxide (drop b y drop) until the color disappears; boil about ten minutes, cool, and titrate as usual. Ores.-Pyrolusite : Dissolve 0.5-1.0 gram of the ore in a casserole, using as small a quantity of dilute hydrochloric acid (I : I) as possible. Add 15 cc. dilute sulfuric acid ( I : 2) and evaporate t o fumes of sulfur trioxide.1 Cool and add I O cc. dilute nitric acid ( I : I ) and about I gram of ammonium persulfate (have the casserole covered). After evolution of gas has ceased, remove cover and take to fumes of sulfur trioxide. Cool, dilute with water, cool again, transfer t o a 2 5 0 cc. flask and dilute t o the mark. Take a n aliquot portion (preferably not less than 0.1 gram of the original ore) and titrate in a volume of about I jo cc., containing 5 grams ammonium fluoride, I O cc. dilute sulfuric acid (I : 2 ) and 2 5 cc. hydrofluoric acid. Ores, Slags, etc., Insoldde in Hydrochloric o r Nitric Acid-Proceed a s in rock, using peroxide treatment if necessary. Spiegels (and Ferromanganese).-Weigh out 0.2-1.0 gram and dissolve in 5-10 cc. dilute nitric acid (I : I ) in a covered casserole; cool slightly and add I gram ammonium persulfate; when action has ceased, remove cover, add 15 cc. dilute sulfuric acid (I : 2 ) and evaporate almostz t o fumes of sulfur trioxide ; cool, add 50-100 cc. w a t e r ; ~heat until ferric salts are All hydrochloric acid must he removed as titrations made with even small amounts of HC1 were decidedly inaccurate. Nitric acid up to 2 cc. concentrated acid in a volume of 150 cc. has no effect on the titration. If any oxidized manganese appears here, treat with hydrogen peroxide as described under Slag.
*
I
126
T H E JOURATALO F I N D U S T R I A L A N D ENGINEERIi\TG
dissolved; cool, place in 250 cc. flask, dilute t o mark a n d take aliquot portions for titration (see conditions under Pyrolusite). For all titrations of spiegels use N / I O (approx.) permanganate solution. The subjoined table gives results of analyses of the various products. Manganese found’ Percentage MnO
Sample Rock A2. . . . . . . . . . . . . . . . Rock 1 . . . . . . . . . . . . . . . . .
...
0.040 0.246 0.316
Rock4 . . . . . . . . . . . . . . . . . Rock 5 , . . . . . . . . . . . . . . .
0.278 0.346
Rock 6 . . . . . . . . . . . . . . . . Rock 7 . . . . . . . . . . . . . . . . Rock 8 . . . . . . . . . . . . . . . . Rock 9 . . . . . . . . . . . . . . . .
............ ............
Rock 12 . . . . . . . . . . . . . . . . Rock 13. . . . . . . . . . . . . . . . Iron slag 1 . . . .. ,
Mn
......... ....
0.04 0.163 0.283 0.183 0.283 0.223 Later Original colorigravimetric3 metric4 0.18 0.16 0.10 0.13 0.07 0.06 0.26 0.25 0.20 0.19 0.13 0.19 0.08 0.08 0.22 0.23 15.88
0.23 0.19 0.09 0.30 0.26 0.21 0.11 0.26 15.91 Percentage
Spiegel 1. . . . . . . . . . . . . . . . Spiegel 2 . . . . . . . . . . . . . . . .
Manganese found by other methods Percentage Mu0
Percentage M n gravimetric phosphate
11.09 21.01 30.55 80.10
11.10 20.99 30.49 80.22
57.09 57.07 57.11
B . of S. certificate High 56.63 LOW 56.15 Average 56.36
dri
..........
1 The results expressed here are the averages of two or more closely agreeing determinations. 2 This is a sample of Bureau of Standards argillaceous limestone, 28, 223. analysis by Hillebrand and Walters. See Jour. Am. Chem. SOC.. a These results were obtained by W. F. Hillebrand some years ago. Concerning them, Dr. Hillebrand writes: “The manganese was determined with the usual care bestowed on rock analyses, but not in duplicate.” And again, “ M y determinations on these particular rocks were made before I began t o determine the small amounts t h a t pass into the filtrates with the lime and magnesia. There was, too, always the possibility, in spite of a basic acetate separation, t h a t a little had not been separated from the F e and Al.” 4 “These tests were made with some care, by the color method, correcting for the i d u e n c e of color due t o the iron content of the rocks.”-W.
F.H. 6
Bureau of Standards analyzed “Sample No. 25.”
The method has been used successfully in this laboratory for some time. Whereas a little experience is required t o accurately determine the end point in titrating large amounts of manganese (40 t o 60 mg.), the end point is sharp and distinct a n d the results are very accurate in determining small amounts of manganese. The difficulties encountered in determining small amounts of manganese in rock and similar materials are known t o analysts and i t is believed t h a t the method here described overcomes these difficulties. It is also believed t h a t the principle involved in the above method may explain some of the discrepancies arising in the determination of ferrous iron in rock. CONTRIBUTION No. 2 14, HAVEMEYER LABORATORIES QUANTITATIVE LABORATORIES COLUMBIA UNIVERSITY
CHEMISTRY
Feb., I913
ANTISEPTIC TESTS O F W O O D PRESERVING OILS’ By A. L. DEAN AND
c. R.
DOWNS
The materials commonly employed for impregnating wood for the purpose of preventing its decay fall readily into two classes-soluble salts and hydrocarbon oils. The most widely used member of the first group is zinc chloride, and of the second, coal tar creosote. Ever since the introduction of this last named material by Bethel1 in 1838 i t has been employed in constantly increasing amounts, and today creosoting-properly performed-is regarded a s the most effective method of timber preservation. I n recent years the large demand for coal t a r creosote and the rather high cost of the treatment with the amounts considered necessary, have led to the use, openly and otherwise, of other materials. Thus the heavy asphaltic petroleum oils have been tried t o some extent, notably in the treatments by the Santa Fe railroad where sufficient of the oil has been injected t o render the wood well-nigh waterproof. The oil distilled from the t a r resulting from the manufacture of carburetted water gas has been used t o a considerable extent, but since its value was uncertain it has been regarded as a n adulterant or substitute for the oils distilled from coal tar. Water gas t a r shows many points of similarity t o coal tar, and the creosote oil distilled from it is very like t h a t distilled from coal tar, although it contains neither the phenols nor the nitrogenous bases characteristic of the latter. Inasmuch a s large quantities of water gas t a r are produced at the gas works in the United States, and the creosote distilled from i t might readily be had in substantial amounts, it is important t o arrive a t a sound estimate of its value a s a timber preservative. The qualities commonly desired in a wood preserving oil are freedom from loss by volatilization, solution or chemical change, and a marked toxicity t o wood-rotting fungi and the animals which destroy timber. I n volatility, solubility and chemical inertness water gas t a r creosote compares favorably with the oils from coal t a r ; the relative antiseptic powers of the two classes of oils are less readily determined. The present communication outlines the results of a laboratory study of the antiseptic powers of oils prepared from coal t a r and water gas tar, and is designed t o assist in arriving at a proper estimate of the place t h a t water gas t a r oils should occupy in timber preservation. The value of water gas t a r creosote as a wood preservative has been the subject of some controversy, but as yet the amount of reliable data has not been large. Practical tests on a commercial scale giving the results of the test of time under service conditions have not been carried out. Where the material h a s been used it has usually been employed in mixture with coal t a r creosote, sometimes without the consumer’s knowledge. The result has been t h a t in t h e absence of reliable information consumers have preferred to rely on coal t a r creosote of the value of which they were certain. 1 Paper presented a t t h e Eighth International Congress of Applied Chemistry, New York, September, 1912.
